From human pituitaries obtained from the National Pituitary Agency in 1971-72, I have stored 115 fractions unfrozen but at 0 degree C usually in the pH range of 3 to 4, and always in 2% butanol. There are also 38 of my earlier solutions. Before storage in solution, I accumulated 30 acetone-dried fractions; and have 10 fractions in acetone in which no MH or STH is expected but which may be explored for other activities. My proposal for 1975-76 is a continuation of attempts to isolate a homogeneous h-MH, or be forced to admit with others that each of these hormones has some intrinsic activity of the other. Since most of my stored fractions are in 10 to 300 microgram amounts, I shall reassay most of them for growth and lactogenic activities, and pool the best of each, and continue my attempts at complete separation. Funds permitting I may assay some preparations with different STH:MH ratios to prove an earlier contention that crop-stimulating activity resides in both hormones. If amounts of potent preparations become available I shall continue tests to determine if this is also true for corpus luteum stimulation. I should also like to have enough h-MH to continue studies on its effectiveness in stimulating lactation in hypophysectomized rats.